Modeling the Properties of Liquid Crystal Electrolytes with Replica Exchange Molecular Dynamics*

Ionic liquid crystals exist at the intersection of ionic liquids and liquid crystals; properties from both classes of materials can be utilized in various applications, from nonlinear optical and photonic devices to dye-sensitized solar cells. One intriguing use has been suggested where the ionic liquid crystals act as anisotropic battery electrolytes, where the liquid crystalline order provides global structure and the ionic liquid character provides a medium through which charge transport is facilitated. The ionic liquid crystals in question have bulky ionic groups and mesogenic “tails” with little or no effective charge, qualitatively similar to charged surfactants. This class of materials is relatively unprobed experimentally, as many are nontrivial to synthesize. We leverage atomistic molecular dynamics simulations of these systems as a preliminary way to study their phase behavior, utilizing replica exchange methods to pinpoint and elucidate the observed phase transitions.